Police say a Ledyard officer shot a monitor lizard to death Sunday afternoon, after a resident called 911 to report what she believed to be an alligator attacking the chickens in her coop.

The officer was forced to shoot the reptile to protect fellow patrolmen, the town's animal control officer and the chickens, police Lt. Michael T. Finkelstein said Monday.

"There really was no safe manner to stop it," Finkelstein said.

Monitor lizards can be as big as some alligators, reaching lengths of 6 to 7 feet.

They are not native to Connecticut and are illegal in the state.

Police believe the one killed Sunday had been an illegal pet that either escaped or was abandoned. Ledyard police warned people that monitor lizards can be dangerous and urged them not to have the large lizards as pets.

Police didn't release the names of the resident who reported the lizard or the officer who shot it.

There had been several reported sightings of a large reptile or alligator in town in the past few months, Finkelstein said. A police officer took a picture of the creature during one of the initial sightings, but it got away, he said.

"We knew for a fact that something was out there," Finkelstein said. "Just locating it was the issue."